Abstract: The 43-year-old Cunninghamia lanceolata large-diameter timber stand was taken as the research object, and three different management modes were set up: selective cutting and intercropping with Castanopsis hystrix (T₁), selective cutting only (T₂), and no selective cutting and no intercropping (T₃). The differences in soil physical and chemical properties, enzyme activities and wood species structure among different modes were compared, and the correlation between soil properties and wood species yield was analyzed. The findings indicated that the average DBH, tree height, and individual tree volume of C. lanceolata large-diameter timber stands under different management modes were all T1 > T2 > T3, and the stand volume was T3 > T1 > T2. The output of C. lanceolata wood species in the three treatments was mainly large-diameter wood. The output and output rate of medium and small-diameter wood were the highest in T₃ treatment and the lowest in T₁ treatment. The output and output rate of large-diameter wood were the highest in T₁ treatment, which were 336.11 m³·hm⁻² and 75.82 %, respectively. The soil bulk density of 3 treatments was proportional to the soil depth. The water content and the contents of organic carbon, total nitrogen, available nitrogen and available potassium decreased with the increase of soil depth. The soil bulk density of each soil layer was T₂ > T₁ > T₃; the water content is T₃ > T₁ > T₂; the T₁ treatment exhibited the highest levels of organic carbon and total nitrogen, whereas the T₃ treatment showed the lowest concentrations of total phosphorus and total potassium.The average soil sucrase activity was the highest in T₁ treatment and the lowest in T₂ treatment. The activities of urease and cellulase were the highest in T₁ treatment and the lowest in T₃ treatment. The catalase activity was the highest in T₃ treatment and the lowest in T₂ treatment. The comprehensive index of soil quality from large to small is T₁ (2.428), T₂ (−1.017), T₃ (−1.411). There was a strong negative correlation between the yield of medium and small diameter timber and the urease activity in 0–10 cm soil layer, and there was a significant positive correlation between the yield of large diameter timber and the soil moisture content in 40–60 cm soil layer. There is a strong negative correlation with bulk density and total potassium content. The improvement effect of T₁ treatment on the soil characteristics of C. lanceolata large-diameter timber stand was better, and it was more conducive to the improvement of the output and output rate of large-diameter C. lanceolata.